A novel method for the preparation of bi-metallic (Pt-Au) nanoparticles on boron doped diamond (BDD) substrate: application to the oxygen reduction reaction

A novel method was developed to synthesize bi-metallic nanoparticles (Au-Pt) on boron-doped diamond (BDD) substrate. This method consisted of (a) deposition of a small amount of gold (equivalent to a few monolayers) by sputtering on the BDD surface, (b) heat treatment of the obtained sample at 600°C in air, resulting in the formation of stable nanoparticles on BDD (Au/BDD electrode), (c) electrodeposition of Pt on the Au/BDD surface occurring preferentially on the Au nanoparticles, and finally (d) heat treatment at 400°C to enhance the interaction between Au and Pt. The ratio between Au and Pt nanoparticles can be modified by modifying the amount of electrodeposited Pt and was estimated using cyclic voltammetry. These Pt-Au/BDD composite electrodes were used to study oxygen reduction using both potential sweep (cyclic voltammetry) and hydrodynamic (turbine electrochemical cell) method

Deposition of clusters and nanoparticles onto boron-doped diamond electrodes for electrocatalysis

Metal and metal oxide particles and nanoparticles, differing from each other by their nature and synthesis technique, were deposited onto boron-doped diamond (BDD) thin film electrodes. The applicability in electrocatalysis of thermally decomposed IrO2 and Au nanoparticles, electrodeposited Pt particles, dendrimer-encapsulated Pt nanoparticles (Pt DENs) and microemulsion-synthesized Pt/Ru nanoparticles was studied, once deposited on BDD substrate. In all cases, the electrochemical response of the composite electrodes could be solely attributed to the supported particles. All the particles, with the exception of Pt DENs, exhibited electrocatalytic activity. Pt DENs inactivity has been attributed to insufficient removal of the dendrimer polymer matrix. It was concluded that the BDD electrode is a suitable substrate for the electrochemical investigation of supported catalytic nanoparticle

Deposition of tin oxide, iridium and iridium oxide films by metal-organic chemical vapor deposition for electrochemical wastewater treatment

In this research, the specific electrodes were prepared by metal-organic chemical vapor deposition (MOCVD) in a hot-wall CVD reactor with the presence of O2 under reduced pressure. The Ir protective layer was deposited by using (Methylcyclopentadienyl) (1,5-cyclooctadiene) iridium (I), (MeCp)Ir(COD), as precursor. Tetraethyltin (TET) was used as precursor for the deposition of SnO2 active layer. The optimum condition for Ir film deposition was at 300 °C, 125 of O2/(MeCp)Ir(COD) molar ratio and 12 Torr of total pressure. While that of SnO2 active layer was at 380 °C, 1200 of O2/TET molar ratio and 15 Torr of total pressure. The prepared SnO2/Ir/Ti electrodes were tested for anodic oxidation of organic pollutant in a simple three-electrode electrochemical reactor using oxalic acid as model solution. The electrochemical experiments indicate that more than 80% of organic pollutant was removed after 2.1 Ah/L of charge has been applied. The kinetic investigation gives a two-step process for organic pollutant degradation, the kinetic was zero-order and first-order with respect to TOC of model solution for high and low TOC concentrations, respectively

When the going gets tough the beautiful get going: aesthetic appeal facilitates task performance.

The current studies examined the effect of aesthetic appeal on performance. According to one hypothesis, appeal would lead to overall decrements or enhancements in performance [e.g. Sonderegger & Sauer, (Applied Ergonomics, 41, 403-410, 2010)]. Alternatively, appeal might influence performance only in problem situations, such as when the task is difficult [e.g. Norman, (2004)]. The predictions of these hypotheses were examined in the context of an icon search-and-localisation task. Icons were used because they are well-defined stimuli and pervasive to modern everyday life. When search was made difficult using visually complex stimuli (Experiment 1), or abstract and unfamiliar stimuli (Experiment 2), icons that were appealing were found more quickly than their unappealing counterparts. These findings show that in a low-level visual processing task, with demand characteristics related to appeal eliminated, appeal can influence performance, especially under duress

Microemulsion-synthesized Pt/Ru/Sn nanoparticles on BDD for alcohol electrooxidation

Ternary Pt-based nanoparticles (nominal composition Pt80Ru10Sn10 ) were synthesized via the microemulsion route and deposited onto boron-doped diamond (BDD) electrode. The particle size measured by transmission electron microscopy was in the 2–5nm diam range. X-ray photoelectron spectroscopy revealed a slightly different surface composition from that of the bulk and showed no chemical shift of the Pt4f7∕2 line in ternary Pt∕Ru∕Sn nanoparticles. For both methanol and ethanol electro-oxidation, the ternary catalyst exhibited lower onset potentials than either pure Pt or the corresponding bimetallic (Pt∕Ru and Pt∕Sn ) catalysts. The ternary Pt∕Ru∕Sn catalyst was more efficient for methanol oxidation than for complete oxidation of ethanol, because ethanol electro-oxidation was stopped at acetaldehyde and/or acetic acid formation, the ternary catalyst being unable to activate the C-C bond scission

Has France become a deficit running country ?

This paper presents an overview of public deficits and debts in France over the three last decades with a special focus on the problem of sustainability of public finances. It identifies the causes of deficits and debt accumulation focusing on both electoral and business cycles. Finally, it deals with changes taken to improve short-term fiscal imbalances and shows that recent structural measures have been undertaken in order to enhance the transparency of the budgetary process to meet public deficit and public spending targets

Through the Looking Glass: What does strategic planning reveal in French local governments?

International audienc